grunt-ttime

Record task completion time as mtime of a file. Use with grunt-find to skip files that haven't changed since the last time a task ran.

npm install --save-dev grunt-ttime

Run ttime:foo to generate a file named foo in the ttime directory (.grunt/ttime by default).

Run ttime:clear to remove all the generated files.

grunt.loadNpmTasks('grunt-ttime');
grunt.loadNpmTasks('grunt-contrib-coffee');

grunt.initConfig({
  ttime: {
    dest: 'build/' // generate files in build/ttime/ instead of .grunt/ttime/
  },

  coffee: {
    all: {
      /* ... */
    }
  }
});

grunt.defineTask('default', ['coffee', 'ttime:coffee']
grunt.defineTask('clean', ['ttime:clear']